The writing has been on the wall for the employees ever since TMT's parent company, CMI Industrial, was liquidated earlier this month.

Attention now turns to the fate of the historic building known as 'The Foundry'.

In its heyday it was one of the largest in the Southern Hemisphere and employed 1,600 workers but it will remain empty until a buyer is found.

Council heritage adviser Stephanie Keays says the building, which opened in the 1870s, is on the State Heritage Register.

"It protects not only the whole site but also brings up the particular buildings that are of higher significance on the site," she said.

"It ensures that there are demolition controls on the site and also the State Government has some leeway if the buildings are allowed to deteriorate too far, they can step in and require for some maintenance to be done."

However, she says the register does allow for development in keeping with its amenity.

The Toowoomba Historical Society says it hopes the building does not fall into a state of disrepair.

"In many developments they take pride in preserving what was there originally and enhancing it to say this is how it started and that attracts [people to] go and have a look at it regardless of what development is on the site," he said.